Interchangeable die collet



Sep. i3, X938. K. A, KUHN v 292948 INTERCHANGEABLE DIE COLLET Filed July 25, 193'/ Z6' INVENTOR ATTORNEYS Patented Sept. 13, 1938 PATENT oFF-ics INTERCHANGEABLE DIE COLLET Karl A. Kuhn, Greenfield, Mass., assigner to Greenfield Tap and Die Corporation, a corporation of Massachusetts Application July 23, 1937, Serial No. 155,162

Claims.

This invention relates to dies and is especially directed to a die collet adapted to hold in accurately clamped position dies of various sizes.

The general purpose of the invention is to pro- 5- vvide a collet adapted for the interchangeable mounting of dies of the sectional type in a wide range of sizes, and particularly to provide means for clamping in the collet dies varying in thickness.

Other objects and advantages will appear from the following specification taken in connection with the accompanying drawing, in which Figure 1 is a top plan View of an assembled collet;

15 Figure 2 is a transverse section on line 2-2 of Figure l;

Figure 3 is a transverse section on line 3--3 of Figure l;

Figure 4 is a sectional View similar to Figure 3 20 illustrating another type of interchangeable clamp-ing elements;

Figure 5 is an expanded view of the construction shown in Figure 4.-;

Figure 6 is a section similar to Figure 3 of another arrangement to the interchangeable clamping structure; and

Figure 7 is an expanded View of the clamping members of Figure 6.

The collet is preferably of the cylindrical type 30 adapted to t into standard sockets in die stocks and the like. The body II is provided with a cylindrical concentric recess I2 forming a cylindrical side wall I3 and a bottom I4 having a central opening i5 of appropriate size and contour for the passage of the work and the discharge of chips.

The collet is particularly adapted to hold in clamped position a die of the sectional type including opposed jaws symmetrically located with "i0 respect to the die axis and capable of longitudinal adjustment. An appropriate embodiment is illustrated, comprising two die jaws I6 having beveled side faces I'l, adapted to rest on the bottorn I4 and to be adjusted longitudinally as by screws I8 in the body I I.

The die jaws I6 are clamped in body Il by clamping segments I9 tting accurately against wall i3 of the recess I2 at opposite sides and provided with beveled inner faces 20 at the same angle as the eiective side faces Il of die section i6. The segments I9 are held in clamping position by screws 2i extending through the bottom oi the body Il. Segments I9 are accurately pro- 55 portioned and shaped to clamp the die jaws I6 in accurate alignment with each other and the axis of the work.

Die jaws I6 lmay be made in various thicknesses;y and an arrangement is provided whereby such jaws `may be interchangeably clamped in the same body II. One construction for this purpose is shown in Figures 4 and 5, and comprises an interchangeable bottom plate 22 fitting accurately on the bottom I4 and provided with a central recess 23 registering with recess I5. Clamping segments 24 are similar in shape and arrangement to segments I9 except for decreased thickness corresponding to the reduced thickness of die jaws 25 in comparison with jaws I6. Clamping screws 26 extend through the bottom of body II and bottom plate 23 into threaded engagement with clamping segments 24, arranged so that when the die jaws 25 are in position and screws 26 are tightened, said jaws will be held rmly in accurately aligned position between segments 24 and against the bottom plate 22.

With this construction it will be apparent that for each thickness of die jaws 25 a corresponding bottom plate 22 and segments 24 may be provided, permitting the use of the body l I and the standard die stocks or the like for a substantial range of die thicknesses, while maintaining flush surfaces at the top and bottom of the collet after the die jaws and clamping structure have been assembled therein.

Another arrangement for the same purpose is illustrated in Figure 6. It is similar in construction to the form shown in Figure 4, except that one of the clamping segments 24 is fixed to the bottom plate 22, and preferably is integral therewith, forming a composite clamping member 21 and reducing the number of parts.

'I'he parts are constructed and arranged to facilitate great accuracy in construction and alignment, and to provide rm positive clamping of die jaws of various sizes. 'I'hey are'designed for ready manufacture on standard machines. The preferred embodiments illustrated herewith have been shown to scale, though various modifications are possible within the scope of the invention as set forth in the claims.

I claim:

1. A die collet comprising a body having a die receiving recess and an interchangeable die-holding unit in the recess, said unit comprising a removable die seat in the bottom of the recess, a die clamp member on the seat at one side of the recess, a separable cooperating die clamp member above the seat at the opposite side of the recess, and means for holding said members and seat in die-holding position in the recess.

2. A die collet comprising a body having a die receiving recess, and an interchangeable dieholding unit in the recess, the unit comprising a removable die seat on the bottom of the recess, a die clamp member on the seat at one side of the recess, having a beveled face positioned to engage one side of a die element, a separable cooperating die clamp member above the seat at the opposite side of the recess and having aI beveled face positioned to engage the other side of a die element, and means including an element engaging the separable member for clamping said unit in operative die-holding position. y

3. An interchangeable die-clamping unit comprising a body of circular disk shape having a cylindrical side Wall or flange and a seat for the bottom of a die element, a die clampingymember mounted on one side of the seat within said side Wall and arranged to engage one side of a die element, a separable member at the other side of the seat within said side wall arranged to engage the opposite side of a die element, and means for holding the separable member in dieclamping relation to the other member and seat comprising retaining means extending upward through said body from the lower surface thereof.

4. An interchangeable die-clamping unit comprising a body of circular disk shape having a cylindrical side Wall or flange and a. die seat adapted to engage the bottom of a die element, a die clamping member integral with the seat Within said side wall and arranged at one side thereof in position to engage a side oi a die element, a separable die clamp member at the other side of the die seat Within said side wall in position to engage the other side of a die element,

KARL A. KUHN. 

